Mold for making shrink-head casings



Feb. 9 1926.

F. H. CHAPIN MOLD FOR MAKING SHRNK HEAD CASING'S y Filed Sept. 16 1925 2 Sheets-Sheet 1 -EwemTor EH: (Zwin,

MOLD FOR MAKING SHRINK HEAD CASINGS Filedspt. le1 1925 2- sheetsfsheet 2 ,:aem-r 'B *L W td frlLchapim Patented Feb. 9, 1926.

FRED H. CHAPIN, OF CLEVELAND, OHIO,

ASSIGNOR TO THE BOURNE-FLLER COM- PANY, OF CLEVELAND, OHIO, A CORPORATION OF OHIO.

MOLD FOR MAKING SHRINK-HEAD CASINGS.

Application led September 16, 1925. Serial No. 56,754.

To al! whom t may concern.'

Be it known that I, FRED H. CHAPIN, a citizen of the United States, residing at Cleveland, in the county of Cuyahoga and 6 State of Ohio, have invented certain new and useful Improvements in Molds for Making Shrink-Head Casings, of which the following is a specication.

This invention relates to molds for mak- 10 ing shrink head casings for ingot molds.

In casting steel ingots, it is customary to pour the molten metal into the mold through what is called a feeder, hot top or shrink head casing into which the molten metal rises during the latter part of the pouring operation and within which a pool of molten metal is maintained long enough to feed the molten metal to the pipe or cavity naturally forming in the solidifying metal so. that whatever pipe or cavity remains in the ingot will be confined within the casing or mold top, thus largely reducing the amount of metal cropped from the ingot before it is rolled into blooms or during the rolling l5 process.

Usually shrink head casings of, this kind have been made of fire clay. I have found however, that the cost of such casings is very largely reduced by making them of blast furnace slag treated in a new way.

In my U. S. Patent No. 1,547,787 of July 28, 1925, I have shown and described a very eflicient shrink head casing made of blast furnace slag and a blinder such as cement treated with a substance which prevents the deleterious action of the gas-producing cbnstituents of the mixture. I have found that while such casings are being molded they contract to a considerable extent and if the inner and outer walls of the mold in which such a casing is formed are rigidly heldV `periods during the molding operatio r- 1 .f` In practice, the inner walls are released as soon as the material has partially set, hardened or solidified or as soon as a .skin has been formed on the surface of the material sufficiently strong to support the softer material within the skin. After this the .partially solidified casing is allowed to rc` main within the outer mold walls until it has hardened to the desired extent when the outer mold walls are released and the casing removed and given further treatment when required.

While the mold constructed in accordance with my invention is especiallydesigned to make shrink head casings of the kind shown, described and claimed in my U. S. patent 'above mentioned, I have found that it is serviceable in molding casings made of properly treated liquid furnace slag and various other materials.

Thenovel features of the mold construc-` y, Figure 2 is a perspective view of parts. of

the mold showing how the mold members are assembled.

Figure 3 shows a horizontal section of the mold in active position for the initial part of the molding operation.

Figure 4 shows a vertical section of the mold with the mold members in the same position as that shown inFigure 3.

Both the inner and outer walls of the mold are composed of a pluralityofA sections.

Walls comprise two similar members A and two similar members B. The members .A are of a general rectangular-shape bein of the same width and height. The mem ers B are of the same size and shape and each of these members B has an' .inwardly projecting ange b at each end. The lower 10o` In the preferred construction, the outer ends of the members A and B are seated in a bottom member C provided with `a recess c extending continuously around the inner side of the bottom member. The lower ends of the members A and B closely iit within the recess c in such manner that they cannot be moved laterally in either direction. These recesses are wide enough to accommodate not only the lower ends of the members li including the flanges t), but also the lower ends ofthe members A. This construction is clearly shown in the drawings. in order to hold the outer walls of the mold firmly in place, i employ loching bars D which have at opposite ends arms ci', which overlap the end portions oit the members A. two arms of cachlocking bar is such as to provide a space d to receive a wedge E. lWhen the wail members A are placed in proper position and the locking bars l) are applied, the wedges may be driven home in such manner as to securely lock the members A -in operative position. The inner walls of the mold are preferably made of eight separate pieces. There are four corner members F, all of the same size and shape and four intermediate members G ali of the same sizey and shape. The members G are T-shaped, having portions g whlch overlap the inner ends of the corner members F and a central portion g which is adapted to enter between the extreme inner ends of two corner members. When the intermediate members G engage the corner members, the inner Wall of the mold as a whole is rigidly held but when the intermediate members are withdrawn, the inner wall of the mold is released from the material being molded. n order to securely lock the inner wall members in place, l employ locking blocks H of the kind shown in Figure 3; two such blocks may beused. They are somewhat longer than the distance between two intermediate members when these members are in locked position. One end of each block H may be curved or rounded as indicated at h and seated in a recess h in one of the members G. The opposite end of the block H may abut against an opposite intermediate member G. It will be understood that only two locking blocks H are necessary, one being employed between each two intermediate members G. A locking ring L is adapted to be seated in rabbets or recesses l formed in the upper ends of the members F and G. The lower ends of the members F and G project into' a re-v cess M in the middle portion ofthe bottom member C and when the ring L is applied and the blocks H are forced into active position, the outer portions of the lower ends of the members F and G are pressed against the inner sides of a rib or flange N 'surrounding the recess M, The ring L The distance between the naef/oe and the flange N limit the outward movement of the members F and G when the bracing blocks H are put under strain.

lWhen the parts are in the condition shown in Figure 3, the material X to be molded may be poured in between the inner and outer walls of the mold and allowed to partially set, harden or solidify. in practice, it is found that a skin such as indicated a't w is formed along the material if the material is allowed to stand for a few minutes, say ten to fifteen minutes. This shin is sufficiently strong to support the softer material within the skin.

When the'parts are in the condition shown 'in Figure 3, the material in a liquid, plastic or semi-duid condition, is poured into the space between the inner and outer mold walls in xthe manner' indicated in Fivure 3 and the material is allowed to partiaiy set, harden or solidify in the manner before described. After this, the bracing blocks H are knocked out of operative position and the inner walls of the mold collapse, in other words, they are withdrawn from contact with the casing being formed so that the casing is allowed to freeiy contract as it naturally does during soiidiiication. lin this way,l prevent the presence of interior strains or stresses in the casing which would occur if freedom of contraction was not provided for. rihe mold walls or sections are of non-resilient or rigid material as shown in the drawings and in the use of the mold the sections are rigidly connected with each other by the fastening devices shown and the mold walls can neither expand nor contract until the fastening devices are released.

'l'n the condition shown in Figure 4, the mold is allowed to stand until the material has set, hardened or solidified to the desired extent throughout the casing and then the locking bars D are removed and allowed to drop away from the casing. The casing is now completely molded. It may 'in some cases be used in this condition or it may be further treated in the manner described in my patent before mentioned or in other ways.

I claim as m invention:

1. A mold or making shrink head casings for ingot molds comprising non-resilient outer walls composed of two sections of approximately the same size and shape and two sections of substantially the same size and shape having flanges at opposite edges which overlap the adjacent edges of the first mentioned sections, means for locking the sections in molding position, non-resilient inner walls composed of se arable sections, and means independent o the first mentioned locking means for holding the inner walls in locked position.

' 2. A mold for making shrink head lcasings for ingot molds Comprising e reed botsubstantially the same size and shape having flanges at opposite ends which overla the adjacent edges of the first mentione sections, and the lower ends of which four sections are seated in said recesses in the bottom member, means for locking the outer Walls in molding position, nonresilient'inner walls composed of separable sections having their lower ends seated in said recesses in the bottom member, and means for holding the innervwalls in locked sition.

3. A mold for molding shrink head cas-.- ings for ingot molds comprising a recessed bottom member, outer walls composed of separable sections having their lower ends seated in said recesses, locking bars and Wedges for holding the outer wall members in position, non-resilient inner walls comosed of separable sections having their ower ends seated in said recesses in the bottom member, a locking ring applied to the upper ends of the inner wall members and bracing` blocks engaging the members of outer wall members flanged at their opposite ends,'rectangular non-resilienwall members interlocking with the rst mentioned memrbers a bottom mold member in which the lower ends of the outer wall members are supported, locking bars and wedges engaging the upper portions of the outer wall members, and non-resilient inner wall members comprising corner sections. and intermediate Sections supported on the. bottom member of the mold, a retaining ring engaging the upper ends of vthe inner Wall members and bracing blocks engaging the members of the inner walls for-locking them in molding osition.

5. A mol for making shrink head casings for ingot molds comprising non-resilient outer walls composed of vseparable sections, means for locldng them in molding osition, and a core for the mold comprising our cor ner members and four spacing members interposed between the four corner members and devices for holding said intermediatel members in position -to thus hold the corner members in place.

In testimony whereof, I have hereunto 55l subscribed my name.

V FI-ns1) H. 'GHAPIN 

